The present invention relates to a shed forming device on an undulated shed loom in which, in operation, sheds form one behind the other in an undulated movement and the shed forming heddles are arranged along flexible cables and held by them, and the cables during the operation of the loom carry out an undulantly advancing movement for the production of which drive points spaced apart from each other are provided on each cable.
In undulated shed looms it is known to form the sheds over the width of the loom by means of groups of heddles. The successive groups carry out their shed forming movements with a difference in phase in the manner that, as a whole, they produce an undulating-like movement which is however divided up stepwise. In this operation it is necessary to equalize the different warp tensions present in the different groups in order to obtain a linear beating-up line in the fabric.
It is also known to arrange the heddles along wires, to bend the wires into an undulated shape, and to change the bends in such a manner that the undulated shape continuously advances. In this connection at the location of each wave bulge there is a shuttle which moves with its wave bulge. The movement of the wires is effected by helically twisted shafts over sliders moved by them and in combination with a back-pull device and therefore in a relatively extremely complicated manner. In another embodiment the wires are bent in undulated shape by shafts arranged alongside of each other. As a result of this arrangement the wires are deflected transversely to the direction of their wave movement, i.e. the heddles which normally lie in a plane come to lie on both sides of said plane at different distances from it.